One class of light source based on a solid-state laser consists of a hybrid structure that combines an excitation light source and a solid-state laser. The excitation light source emits light that differs in wavelength from that of the solid state laser. For example, this type of source is utilized to provide wavelength conversions. In addition, by passing the light from the laser light source through a nonlinear optical crystal, devices that generate multiple wavelengths such as the second harmonic of the solid-state laser may be fabricated. Such lasers are described in Introduction to Optical Electronics by Amnon Yariv (third edition, published in 1985, 1976, 1971 by Holt, Rinehart and Winston, Inc.; translated into Japanese by Kunio Tada and Takeshi Kamiya, Nov. 25, 1988, published by Maruzen), and hence, will not be discussed in detail here.
There are a number of problems which add to the cost of constructing such light sources. First, the excitation light source and solid-state laser are fabricated separately. These components must be placed in exact positions relative to one another. This alignment step substantially increases the cost of fabrication. In addition, the resulting device is substantially larger than the solid-state laser. It is advantageous to provide as compact a device as possible.
Second, once aligned, the components must be protected from mechanical vibrations that can alter the alignment of the components. In prior art devices, the components must be mounted on a vibration isolating base. This base further increases the complexity, cost, and size of the final devices, and hence, detracts from the commercial use of such devices.
Broadly, it is the object of the present invention to provide an improved hybrid laser device.
It is a further object of the present invention to provide a light source device in which the excitation source and solid-state laser are fabricated on the same substrate in precise alignment with one another.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.